Pump is very noisy with a loud grinding or screeching sound while running

Safety first: Turn off power at the breaker before touching the pump or motor.

• Isolate the noise: Use a mechanic's stethoscope or a long screwdriver held to your ear to confirm the noise is coming from the motor body, not the wet end or plumbing.
• Check for shaft play: With power OFF, remove the rear motor cover and try to move the shaft side-to-side. Excessive play indicates bearing wear.
• Inspect for seal leaks: Look for rust or water marks at the motor face where it meets the Harris pump housing. A failed shaft seal can allow water into the bearings.

Motor bearing replacement requires press tools and experience; in most residential cases, replacing the complete Harris motor assembly or pump head is recommended.